<!DOCTYPE html>
<html lang="en" >
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <script src="js/vue-2.6.12.js"></script>
</head>
<body>

<div id="app">

  <h1>{{count}} </h1>

  <button type="button" @click="decrement">-1</button>
  <button type="button" v-on:click="increment">+1</button>

</div>


<script>

  let app = new Vue({

    el:"#app",
    data:{
     count: 0,
    },
    methods:{

     increment(){
       this.count++;
     },

      decrement(){
       this.count--;
      },



    }

  });

</script>

</body>
</html>